School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China.
Ultrason Sonochem. 2013 Nov;20(6):1408-13. doi: 10.1016/j.ultsonch.2013.04.012. Epub 2013 May 9.
This research explores the mechanism of ultrasonic pretreatment on enzymolysis of defatted wheat germ protein (DWGP). The enzymolysis reaction kinetics and thermodynamics were studied after ultrasonic pretreatments using a probe-type sonicator and an ultrasonic cleaning bath, and the results were compared with traditional enzymolysis. The results showed that both the traditional and ultrasonic pretreated enzymolysis fit well to first-order kinetics. Both the temperature and ultrasound had a positive effect on the enzymolysis of DWGP, with temperature playing a dominant role. Under the optimized conditions of DWGP concentration of 1% (w/v), Alcalase concentration of 2000 U/g, time of 10 min and temperature of 50 °C, both the probe and cleaning bath ultrasonic pretreated enzymolysis showed high polypeptide concentrations (231.019 and 231.320 μg/mL) and low energy requirements. In comparison with traditional enzymolysis, these methods significantly increased the reaction rate constant (k) by 166.7% and 144.4%, 92.9% and 85.7%, 28.0% and 28.0%, 16.1% and 12.9% at 20, 30, 40 and 50 °C, and decreased the activation energy (Ea), enthalpy of activation (ΔH), Gibbs free energy of activation (ΔG) and entropy of activation (ΔS) by 68.6% and 62.4%, 74.1% and 67.5%, 34.3% and 31.2%, 1.4% and 1.3%. It can be concluded that ultrasonic pretreatment of DWGP can remarkably improve the enzymolysis efficiency and consequently leads to the production of higher polypeptide yield.
本研究探索了超声预处理对脱脂小麦胚芽蛋白（DWGP）酶解机制的影响。使用探针式超声仪和超声清洗槽进行超声预处理后，研究了酶解反应动力学和热力学，并将结果与传统酶解进行了比较。结果表明，传统和超声预处理的酶解均符合一级动力学。温度和超声对 DWGP 的酶解均有积极影响，其中温度起主导作用。在 DWGP 浓度为 1%（w/v）、Alcalase 浓度为 2000 U/g、时间为 10 min 和温度为 50°C 的优化条件下，探针和清洗槽超声预处理的酶解均表现出较高的多肽浓度（231.019 和 231.320 μg/mL）和较低的能量需求。与传统酶解相比，这些方法使反应速率常数（k）分别提高了 166.7%和 144.4%、92.9%和 85.7%、28.0%和 28.0%、16.1%和 12.9%，在 20、30、40 和 50°C 下，同时降低了活化能（Ea）、活化焓（ΔH）、活化自由能（ΔG）和活化熵（ΔS）分别为 68.6%和 62.4%、74.1%和 67.5%、34.3%和 31.2%、1.4%和 1.3%。综上所述，DWGP 的超声预处理可以显著提高酶解效率，从而导致更高的多肽产率。
